Generation method for 3d asteroid dynamic map and portable terminal

ABSTRACT

The present invention provides a generation method for a 3D asteroid dynamic map and a portable terminal. The method comprises: obtaining a panorama image; identifying the panorama image and segmenting into a sky region, a human body region, and a ground region; calculating a panoramic depth map for the sky region, the human body region, and the ground region; respectively transforming the panorama image and the panoramic depth map to generate an asteroid image and an asteroid depth map; generating an asteroid view under a virtual viewpoint; and rendering to generate a 3D asteroid dynamic map. By automatically generating the asteroid view under the virtual viewpoint, and synthesizing and rendering same, the technical solution of the present invention generates the asteroid dynamic map having a 3D effect from the panorama image.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a National Phase of International ApplicationNo. PCT/CN2019/112246, filed on Oct. 21, 2019 which claims priority toChinese Patent Application No. 201910057169.3, filed on Jan. 22, 2019and entitled “Generation Method for 3D Asteroid Dynamic Graph andPortable Terminal”, and the contents of which are herein incorporated byreference in their entireties.

TECHNICAL FIELD

The present disclosure relates to the field of images, and particularlyto a method for generating a 3D asteroid dynamic graph and a portableterminal.

BACKGROUND

Currently, there are already some methods to generate a 3D view from animage, for example, using the micro-lens technology to generate a 3Dview. The lens of the micro-lens is a magnifying lens array which isdesigned to magnify different images when viewed from slightly differentangles. In order to generate the 3D view, it is first necessary togenerate a multi-viewpoint image, such as 12-viewpoint or more viewpointimages, and then the multi-viewpoint image is mixed into a mixed image.The mixing of the multi-view images means a process of extractingsuitable pixels from the multi-viewpoint image and combining them into anew image. The new image contains multi-viewpoint information of theoriginal image. The lens of the micro-lens is configured to displaythese multi-viewpoint images at different viewpoints. Finally, throughthe micro-lens board, the viewer's left and right eyes can see differentimages, thereby producing a 3D effect. The disadvantage of this methodis that it requires the use of the micro-lens board rather than nakedeyes to view.

Another commonly used method is to manually convert a 2D image into amulti-viewpoint image. The operator usually needs to create a skin toextract an object from a target image, and then determines depthinformation for the skin according to own judgment. The depthinformation has a grayscale image with the same size as the original 2Dimage; and the gray in the grayscale image represents a depth of eachportion in the image. The manually created depth information isconfigured to guide the computer to move the pixels of the original 2Dimage to form a new viewpoint map. A depth map can produce a strong 3Ddisplay effect. However, it takes hours or even days to generate a 3Dview by using such existing method.

In view of this, the existing method and system for generating a 3D viewfrom an image have disadvantages such as requiring tools or longprocessing time, and the user experience is not high.

SUMMARY Technical Problem

The present disclosure provides a method for generating a 3D asteroiddynamic graph, a computer-readable storage medium and a portableterminal, which aims to automatically generate asteroid views undervirtual viewpoints, and synthesize the render the asteroid views togenerate an asteroid dynamic graph with a 3D effect from one panoramicimage. The method has a high efficiency, the image quality is good, andthe user experience is higher.

Technical Solution

In the first aspect, the present disclosure provides a method forgenerating a 3D asteroid dynamic graph, including:

acquiring a panoramic image;

identifying and partitioning the panoramic image into a sky area, ahuman body area and a ground area;

calculating a panoramic depth map for the sky area, the human body areaand the ground area respectively;

transforming the panoramic image and the panoramic depth maprespectively to generate an asteroid image and an asteroid depth map;

generating an asteroid view under a virtual viewpoint;

generating a 3D asteroid dynamic graph by rendering a plurality ofasteroid views under a plurality of virtual viewpoints.

In the second aspect, the present disclosure provides computer-readablestorage medium that stores one or more computer programs, the one ormore computer programs, when executed by a processor, implement thesteps of the method for generating the 3D asteroid dynamic graph:

acquiring a panoramic image;

identifying and partitioning the panoramic image into a sky area, ahuman body area and a ground area;

calculating a panoramic depth map for the sky area, the human body areaand the ground area respectively;

transforming the panoramic image and the panoramic depth maprespectively to generate an asteroid image and an asteroid depth map;

generating an asteroid view under a virtual viewpoint;

generating a 3D asteroid dynamic graph by rendering a plurality ofasteroid views under a plurality of virtual viewpoints.

In the third aspect, the present disclosure provides a portableterminal, including:

one or more processors;

a memory; and

one or more computer programs, wherein the one or more computer programsare stored in the memory and configured to be executed by the one ormore processors, the processors, when executing the computer programs,implement the steps of the method for generating the 3D asteroid dynamicgraph:

acquiring a panoramic image;

identifying and partitioning the panoramic image into a sky area, ahuman body area and a ground area;

calculating a panoramic depth map for the sky area, the human body areaand the ground area respectively;

transforming the panoramic image and the panoramic depth maprespectively to generate an asteroid image and an asteroid depth map;

generating an asteroid view under a virtual viewpoint;

generating a 3D asteroid dynamic graph by rendering a plurality ofasteroid views under a plurality of virtual viewpoints.

Advantages

In the technical solution of the present disclosure, by calculating theimage depth map, automatically generating the asteroid views under thevirtual viewpoints, and synthesizing the rendering the asteroid views,an asteroid dynamic graph with a 3D effect is generated from onepanoramic image, which not only enhances the visual effect, but also hasadvantages such as a fast processing speed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart showing a method for generating a 3D asteroiddynamic image according to an embodiment I of the present disclosure.

FIG. 2 is an example of a panoramic depth map according to theembodiment I of the present disclosure.

FIG. 3 is a flow chart showing a method for mapping an asteroid image toa panoramic image according to the embodiment I of the presentdisclosure.

FIG. 4 is a flow chart showing a method for generating an asteroid viewunder a virtual viewpoint according to the embodiment I of the presentdisclosure.

FIG. 5 is a schematic structure diagram of a portable terminal accordingto an embodiment III of the present disclosure.

DETAILED DESCRIPTION

In order to make the objectives, technical solution, and advantages ofthe present disclosure clearer, the present disclosure will be describedin detail with reference to the accompanying drawings and embodiments.It should be appreciated that the specific embodiments described hereare only used for explaining the present disclosure, rather thanlimiting the present disclosure.

In order to illustrate the technical solution of the present disclosure,specific embodiments are used for description below.

Embodiment I

Referring to FIG. 1, a method or generating a 3D asteroid dynamic graphprovided by the Embodiment 1 of the present disclosure includes thefollowing steps.

S101: a panoramic image is acquired.

A panoramic image is acquired. The panoramic image can be generated bymultiple fisheye images taken by at least two fisheye lenses through anoptical flow stitching algorithm. The content of the panoramic image caninclude a picture taken by a panoramic camera held by a photographer.

S102: the panoramic image is identified and partitioned into a sky area,a human body area and a ground area.

The sky and the human body are identified from the panoramic imagecontent and a semantic partition is performed. There are mainly threeareas through the partition: sky area, human body area, and ground area.

The identifying and partition of the sky area can be performed by usinga classical sky detection algorithm. The sky detection algorithm is notlimited to the methods disclosed in the paper “Sky Region Detection in aSingle Image for Autonomous Ground Robot Navigation” and the Chinesepatent CN109003237A. The identifying and partition of the human body canbe performed by using a classical image target detection algorithm. Thetarget detection algorithm is not limited to a method disclosed in thedocument “Cascade R-CNN: Delving into High Quality Object Detection”,etc. After the sky area and the human body area are partitioned, theremaining portion is all partitioned into the ground area, that is, theground area can include a tall building, a house, a tree, etc.

S103: the panoramic depth map is calculated for the sky area, the humanbody area and the ground area;

The relative depth between different objects can reflect athree-dimensional position relationship between the objects. The depthof an object represents a distance between the object and a camera in anactual scene. Therefore, the farther the object is from the camera, thegreater the depth value; and the closer the object to the camera, thesmaller the depth value.

The panoramic depth map is calculated according to the sky area, thehuman body area, and the ground area; and the process is provided asfollows.

The depth value bodyDepth of a pixel (x₁, y₁) in the human body area canbe calculated by a formula (1):

$\begin{matrix}{{bodyDepth} = {{\min\;{BodyDepth}} + \frac{( {y_{1} - {\min\;{RowIdx}}} ) \cdot ( {{\max\;{BodyDepth}} - {\min\;{BodyDepth}}} )}{{\max\;{RowIdx}} - {\min\;{RowIdx}}}}} & (1)\end{matrix}$

In the above formula (1), y₁ is the row-coordinate of the pixel (x₁, y₁)in the panoramic image, x ∈[minRowIdx, maxRowIdx]; minRowIdx is theminimum value of an row-coordinate of a pixel in the human body area;maxRowIdx is the maximum value of the row-coordinate of the pixel in thehuman body area; minBodyDepth is set as the minimum value of a pixeldepth value in the human body area; maxBodyDepth is set as the maximumvalue of the pixel depth value in the human body area, where bodyDepth E[minBodyDepth, maxBodyDepth].

The depth value of all pixels in the sky area is set to a fixed valueskyDepth, and skyDepth∈(maxBodyDepth, 255].

The pixel (x₂, y₂) in the ground area are partitioned into a fixed depthvalue area and a gradient depth value area.

A range of the row-coordinate of the fixed depth area is[2maxRowIdx-imgH, imgH], where imgH is a height of the image, that is,the maximum value of the row-coordinate, so that the depth value of thepixel in the fixed depth area is set as the fixed value maxBodyDepth.

The area in the ground area except for the fixed depth area is thegradient depth value area. The depth value of the pixel (x₂, y₂) in thegradient depth value area can be calculated by a formula (2):

$\begin{matrix}{{gradulDepth} = {{edgeDepth} + \frac{y_{2} \cdot ( {{\max\;{BodyDepth}} - {edgeDepth}} )}{lowldx}}} & (2)\end{matrix}$

In the formula (2), y₂ is the row-coordinate of the pixel (x₂, y₂) inthe panoramic image, and y₂<2maxRowIdx-imgH; edgeDepth is a set fixedvalue, and edgeDepth E [maxBodyDepth, skyDepth).

After the depth value of the human body area, the depth value of the skyarea and the depth value of the ground area are calculated respectively,the panoramic depth map can be obtained, referring to FIG. 2 for anexample of the panoramic depth map.

S104: the panoramic image and the panoramic depth map are transformedrespectively to generate the asteroid image and the asteroid depth map.

Referring to FIG. 3, a method for mapping the asteroid image to thepanoramic images includes the following steps.

S1041: the coordinate of the pixel point in the asteroid image istransformed from an image coordinate system to a physical coordinatesystem.

A south pole point of a unit ball is taken as an origin of thethree-dimensional coordinates, the x-axis is to the right, the y-axis isvertically inward, and the z-axis is upward, such arrangement conformsto the right-handed coordinate system. A view point of the observer isset to be located on a line between a north pole point and a center ofthe unit ball; a coordinate value is denoted as (0,0,d); it is set thata projected asteroid plane is tangent to the unit ball at the coordinateorigin (0,0,0); an outputted asteroid image size is set as (W, II); acoordinate (u, v) of a pixel point in the asteroid image is transformedas a coordinate (U, V) in the physical coordinate system; and thecalculation formulas for U and V are a formula (3) and a formula (4)respectively as follows:

$\begin{matrix}{U = {\frac{L \cdot u}{W} - \frac{L}{2}}} & (3) \\{V = {\frac{L}{2} - \frac{L \cdot v}{H}}} & (4)\end{matrix}$

In the formulas (3) and (4), L=2 ·Radius·tan(fov·0.5),

${fov} = {120 \cdot \frac{\pi}{180}}$

is a transformation formula of radian system when an angle of view isset to 120° and a radius of the unit ball satisfies that Radius=1.

S1042: an azimuth angle φ of the pixel point in a spherical coordinatesystem is calculated; where the pixel point has the coordinate in thephysical coordinate system.

The calculation formula for Ω is as follows:

$\begin{matrix}{\varphi = \{ \begin{matrix}{a{\cos( \frac{U}{r} )}} & {{{if}\mspace{14mu} V} \geq 0} \\{{2 \cdot \pi} - {a\mspace{11mu}{\cos( \frac{U}{r} )}}} & {{{if}{\;\mspace{9mu}}V} < 0}\end{matrix} } & (5)\end{matrix}$

In the above formula (5), r is a radius of a latitude circle of thepoint (U, V) in the spherical coordinate system, r=√{square root over(U·U+V·V)}.

S1043: a zenith angle θ of the pixel point in the spherical coordinatesystem is calculated; where the pixel point has the coordinate in thephysical coordinate system.

The tangent theorem and the sine theorem are utilized to calculate thezenith angle θ of the point (U, V) in the spherical coordinate system.The calculation formula is as follows:

θ=π−α−β  (6)

In the formula (6),

${\alpha = {\arctan 2( \frac{r}{d} )}},{\beta = {{\arcsin( {d \cdot {\sin(a)}} )}.}}$

S1044: the transformation formula between the pixel point (θ, φ) in thespherical coordinate system and the pixel point (x, y) in the panoramicimage is calculated.

The latitude and longitude expansion method is utilized to project thespherical coordinate (θ, φ) to the panoramic image coordinate (x, y).The calculation formula for x is as follows:

$\begin{matrix}{x = {( {{2 \cdot \pi} - \varphi} ) \cdot \frac{imgW}{2 \cdot \pi}}} & (7)\end{matrix}$

The calculation formula for y is as follows:

$\begin{matrix}{y = {\theta \cdot \frac{imgH}{\pi}}} & (8)\end{matrix}$

According to the above method for mapping the asteroid image to thepanoramic image, a reverse mapping method can be utilized to obtain theasteroid image from the panoramic image. The reverse mapping methodspecifically includes following steps.

A corresponding coordinate value in the panoramic image is reverselycalculated from the coordinate value in the asteroid image.

Since the calculated coordinate value is floating-point type data, it isnecessary to use bilinear interpolation algorithm to calculate a pixelvalue of the pixel point (u, v) in the asteroid image.

All the pixel points in the panoramic image are traversed, and anasteroid view can be calculated and generated.

An asteroid view is generated from the panoramic image obtained in thestep S101.

An asteroid depth map is generated from the panoramic depth mapcalculated in the step S103.

S105: an asteroid view under a virtual viewpoint is generated accordingto the asteroid image and the asteroid depth map.

Referring to FIG. 4, the steps of generating the asteroid view under thevirtual viewpoint according to the asteroid image and the asteroid depthmap includes the following steps.

S1051: a coordinate of a virtual viewpoint is set.

A real viewpoint of the asteroid image is directly above the asteroidimage. A virtual viewpoint is set on a unit circular trajectory centeredon the real viewpoint and parallel to the asteroid image. The coordinateof the virtual viewpoint is (x, y), with x=cos (θ), y=sin(θ), θ∈ [0,2.π]; the number of virtual viewpoints is n, and n>1.

S1052: a translation matrix T from the real viewpoint to the virtualviewpoint is calculated.

T is a 3*3 matrix, and is calculated by following formula (9):

$\begin{matrix}\{ \begin{matrix}{T_{x} = x} \\{T_{y} = y} \\{T_{z} = 0}\end{matrix}  & (9)\end{matrix}$

S1053: a rotation matrix R between the real viewpoint and the virtualviewpoint is calculated.

R is a 3*3 matrix, and is calculated by following formula (10):

$\begin{matrix}\{ \begin{matrix}{R_{x} = {x \cdot \frac{\pi}{60}}} \\{R_{y} = {y \cdot \frac{\pi}{60}}} \\{R_{z} = 0}\end{matrix}  & (10)\end{matrix}$

S1054: the asteroid view under the virtual viewpoint is generated byusing a 3D warping algorithm according to the asteroid image and theasteroid depth map.

The 3D warping algorithm includes the following steps.

A two-dimensional image coordinate in an RGB image of the asteroid imageand a corresponding depth value in the asteroid depth map are read; andthe two-dimensional coordinate point q is backprojected to the realthree-dimensional coordinate point P.

The real three-dimensional coordinate point P is rotated or translatedto generate P′.

The rotated or translated virtual three-dimensional coordinate point P′is re-projected onto the two-dimensional image plane under the virtualviewpoint to generate a two-dimensional coordinate point q′; the depthvalue reflects a front and back occlusion relationship between thethree-dimensional objects in the projection process.

The projection formula of the asteroid view under the virtual viewpointis shown as a formula (11):

q′=K·R·K ⁻¹ ·q+K·T  (11)

In the above formula (11), P is the real three-dimensional coordinatepoint, q is the two-dimensional coordinate point of P projected onto thetwo-dimensional image plane, q=K·P; P′ is the virtual three-dimensionalcoordinate point; and a relationship between the virtualthree-dimensional coordinate point P′ and the real three-dimensionalcoordinate point P is P′=R·P+T. q′ is the two-dimensional coordinatepoint of P′ projected onto the two-dimensional image plane; q′=K·P′, andK is an internal parameter matrix of the camera; the virtual camera andthe real camera are arranged to have the same internal parameters.

In the process of using the 3D warping algorithm to generate theasteroid view under the virtual viewpoint, a void area without pixelinformation generated by the object in the original asteroid image dueto the front and back occlusion is filled with adjacent pixel points.

In the generation of the asteroid view under the virtual viewpoint,since there are n virtual viewpoints (x, y), n asteroid views under then virtual viewpoints can be generated, n>1.

S106: the 3D asteroid dynamic graph is generated by rendering aplurality of asteroid views under a plurality of virtual viewpoints.

n virtual viewpoints on the unit circular trajectory are utilized togenerate n asteroid views under the n virtual viewpoints; the n asteroidviews are synthesized and rendered according to a sequence or a setorder of the asteroid views generated under the virtual viewpoints, togenerate the asteroid dynamic graph with a 3D effect. n is a positiveinteger.

Embodiment II

The embodiment II of the present disclosure provides a computer-readablestorage medium, and when the computer program is executed by aprocessor, the steps of the method for generating a 3D asteroid dynamicgraph provided in the embodiment I of the present disclosure areimplemented.

The computer-readable storage medium can be a non-transitorycomputer-readable storage medium.

Embodiment III

FIG. 5 shows a specific structure block diagram of a portable terminalprovided in embodiment III of the present disclosure. The portableterminal 100 includes: one or more processors 101, a memory 102, and oneor more computer programs; the processor 101 is connected to the memory102 by a bus; the one or more computer programs are stored in the memory102, and are configured to be executed by the one or more processors101; and the processor 101, when executing the computer programs,implements the steps of the method for generating a 3D asteroid dynamicgraph provided in the embodiment I of the present disclosure.

In the embodiments of the present disclosure, those of ordinary skill inthe art can understand that all or part of the steps in the methods ofthe above-mentioned embodiments can be implemented by a programinstructing relevant hardware, and the program can be stored in acomputer-readable storage medium. The storage medium mentioned is, suchas ROM/RAM, a magnetic disk, an optical disk, etc.

The above are merely the preferred embodiments of the present disclosureand are not intended to limit the present disclosure. Any modification,equivalent replacement and improvement made within the spirit andprinciple of the present disclosure shall be regarded as the protectionscope of the present disclosure.

In the present disclosure, by calculating the image depth map,automatically generating, synthesizing and rendering the asteroid viewsunder the virtual viewpoints, the asteroid dynamic graph with the 3Deffect is generated from one panoramic image, which not only enhancesthe visual effect, but also has advantages such as a fast processingspeed.

What is claimed is:
 1. A method for generating a 3D asteroid dynamicgraph, comprising: acquiring a panoramic image; identifying andpartitioning the panoramic image into a sky area, a human body area anda ground area; calculating a panoramic depth map for the sky area, thehuman body area and the ground area respectively; transforming thepanoramic image and the panoramic depth map respectively to generate anasteroid image and an asteroid depth map; generating an asteroid viewunder a virtual viewpoint; generating a 3D asteroid dynamic graph byrendering a plurality of asteroid views under a plurality of virtualviewpoints.
 2. The method for generating the 3D asteroid dynamic graphaccording to claim 1, wherein the identifying and partitioning thepanoramic image into the sky area, the human body area and the groundarea comprises: identifying the sky area and the human body area in thepanoramic image, then partitioning the panoramic image into the sky areaand the human body area, and partitioning a remaining portion of theimage as the ground area.
 3. The method for generating the 3D asteroiddynamic map according to claim 1, wherein the calculating the panoramicdepth map comprises calculating a depth value of the sky area, a depthvalue of the human body area and a depth value of the ground arearespectively; wherein, a depth value bodyDepth of a pixel (x₁, y₁) inthe human body area is calculated by a formula (1):bodyDepth=min BodyDepth+(y ₁−min RowIdx)·(max BodyDepth−minBodyDepth)/max RowIdx−min RowIdx  (1), in the formula (1), y₁ is anrow-coordinate of the pixel (x₁, y₁) in the panoramic image,x∈[minRowIdx, maxRowIdx], minRowIdx is a minimum value of arow-coordinate of the pixel in the human body area, maxRowIdx is amaximum value of the row-coordinate of the pixel in the human body area,minBodyDepth is a set minimum value of a depth value of the pixel in thehuman body area, maxBodyDepth is a set maximum value of the depth valueof the pixel in the human body area, and bodyDepth∈[minBodyDepth,maxBodyDepth]; depth values of all pixels in the sky area are set to afixed value skyDepth, and skyDepth∈(maxBodyDepth, 255]; pixels (x₂, y₂)in the ground area are partitioned into a fixed depth value area and agradient depth value area; a range of the row coordinates of the fixeddepth area is [2maxRowIdx-imgH, imgH], where imgH is a height of thepanoramic image, that is, a maximum value of the row coordinate of thepixel in the panoramic image, the depth value of the pixel in the fixeddepth area is set to the fixed value maxBodyDepth; an area outside thefixed depth area in the ground area is taken as the gradient depth valuearea, and a depth value of the pixel (x₂, y₂) in the gradient depthvalue area can be calculated by a formula (2): $\begin{matrix}{{{gradulDepth} = {{edgeDepth} + \frac{y_{2} \cdot \begin{pmatrix}{{\max\mspace{11mu}{BodyDepth}} -} \\{edgeDepth}\end{pmatrix}}{lowIdx}}},} & (2)\end{matrix}$ in the formula (2), y₂ is the row coordinate of the pixel(x₂, y₂) in the panoramic image, y₂<2maxRowIdx-imgH, edgeDepth is a setfixed value, and edgeDepth∈[maxBodyDepth, skyDepth).
 4. The method forgenerating the 3D asteroid dynamic graph according to claim 1, whereinthe generating an asteroid view under a virtual viewpoint comprises:setting a coordinate of the virtual viewpoint; wherein a real viewpointof the asteroid image is directly above the asteroid image, the virtualviewpoint is set on a unit circular trajectory centered on the realviewpoint and parallel to the asteroid image, the coordinate of thevirtual viewpoint is (x, y), and x=cos (θ), y=sin(θ), θ∈[0, 2·π];calculating a translation matrix T from the real viewpoint to thevirtual viewpoint; wherein T is a 3*3 matrix, and is calculated by aformula (9): $\begin{matrix}\{ {\begin{matrix}{T_{x} = x} \\{T_{y} = y} \\{T_{z} = 0}\end{matrix};}  & (9)\end{matrix}$ calculating a rotation matrix R from the real viewpoint tothe virtual viewpoint; wherein R is a 3*3 matrix, and is calculated by aformula (10): $\begin{matrix}\{ {\begin{matrix}{R_{x} = {x \cdot \frac{\pi}{60}}} \\{R_{y} = {y \cdot \frac{\pi}{60}}} \\{R_{z} = 0}\end{matrix};}  & (10)\end{matrix}$ generating the asteroid view under the virtual viewpointby using a 3D warping algorithm according to the asteroid image and theasteroid depth map; wherein the 3D warping algorithm comprises:acquiring a two-dimensional image coordinate in an RGB image of theasteroid image and a corresponding depth value in the asteroid depthmap, and backprojecting a two-dimensional coordinate point q to a realthree-dimensional coordinate point P; rotating or translating the realthree-dimensional coordinate point P to generate P′; re-projecting therotated or translated virtual three-dimensional coordinate point P′ to atwo-dimensional image plane under the virtual viewpoint to generate atwo-dimensional coordinate point q′; wherein the depth value reflects afront and back occlusion relationship between three-dimensional objectsin a projection process; wherein a projection formula of the asteroidview under the virtual viewpoint is shown as a formula (11):q′=K·R·K ⁻¹ ·q+K·T  (11), in the formula (11), wherein P is the realthree-dimensional coordinate point, q is the two-dimensional coordinatepoint of P projected onto the two-dimensional image plane, q=K·P, P′ isthe virtual three-dimensional coordinate point, a relationship betweenthe virtual three-dimensional coordinate point P′ and the realthree-dimensional coordinate point P satisfies P′=R·P+T; q′ is thetwo-dimensional coordinate point of P′ projected onto thetwo-dimensional image plane, q′=K·P′, K is an internal parameter matrixof a camera, a virtual camera and a real camera are arranged to have asame internal parameter.
 5. The method for generating the 3D asteroiddynamic graph according to claim 4, wherein in the generated asteroidview under the virtual viewpoint, since there are n virtual viewpoints(x, y), n asteroid views under the n virtual viewpoints are generated,and n>1.
 6. The method for generating the 3D asteroid dynamic graphaccording to claim 4, wherein, in the asteroid view under the virtualviewpoint generated by using the 3D warping algorithm, a void areawithout pixel information generated by an object in the originalasteroid image due to the front and back occlusion is filled with anadjacent pixel point.
 7. The method for generating the 3D asteroiddynamic graph according to claim 1, wherein the generating the 3Dasteroid dynamic graph by rendering the plurality of asteroid viewsunder the plurality of virtual viewpoints comprises: using n virtualviewpoints on the unit circular trajectory to generate n asteroid viewsunder the n virtual viewpoints, synthesizing and rendering the nasteroid views in an order to generate the 3D asteroid dynamic graph,and n is a positive integer.
 8. A computer-readable storage medium thatstores one or more computer programs, wherein, the one or more computerprograms, when executed by a processor, implements the steps of themethod for generating the 3D asteroid dynamic graph: acquiring apanoramic image; identifying and partitioning the panoramic image into asky area, a human body area and a ground area; calculating a panoramicdepth map for the sky area, the human body area and the ground arearespectively; transforming the panoramic image and the panoramic depthmap respectively to generate an asteroid image and an asteroid depthmap; generating an asteroid view under a virtual viewpoint; generating a3D asteroid dynamic graph by rendering a plurality of asteroid viewsunder a plurality of virtual viewpoints.
 9. A portable terminal,comprising: one or more processors; a memory; and one or more computerprograms, wherein the one or more computer programs are stored in thememory and configured to be executed by the one or more processors, theprocessors, when executing the computer programs, implement the steps ofthe method for generating the 3D asteroid dynamic graph: acquiring apanoramic image; identifying and partitioning the panoramic image into asky area, a human body area and a ground area; calculating a panoramicdepth map for the sky area, the human body area and the ground arearespectively; transforming the panoramic image and the panoramic depthmap respectively to generate an asteroid image and an asteroid depthmap; generating an asteroid view under a virtual viewpoint; generating a3D asteroid dynamic graph by rendering a plurality of asteroid viewsunder a plurality of virtual viewpoints.
 10. The portable terminalaccording to claim 9, wherein the identifying and partitioning thepanoramic image into the sky area, the human body area and the groundarea comprises: identifying the sky area and the human body area in thepanoramic image, then partitioning the panoramic image into the sky areaand the human body area, and partitioning a remaining portion of theimage as the ground area.
 11. The portable terminal according to claim9, wherein the calculating the panoramic depth map comprises calculatinga depth value of the sky area, a depth value of the human body area anda depth value of the ground area respectively; wherein, a depth valuebodyDepth of a pixel (x₁, y₁) in the human body area is calculated by aformula (1): $\begin{matrix}{{{bodyDepth} = {{\min\mspace{11mu}{BodyDept}} + \frac{\begin{matrix}{( {y_{1} - {\min\mspace{11mu}{RowIdx}}} ) \cdot} \\\begin{pmatrix}{{\max\mspace{11mu}{BodyDepth}} -} \\{\min\mspace{11mu}{BodyDepth}}\end{pmatrix}\end{matrix}}{{\max\mspace{11mu}{RowIdx}} - {\min\mspace{11mu}{RowIdx}}}}},} & (1)\end{matrix}$ in the formula (1), y₁ is an row-coordinate of the pixel(x₁, y₁) in the panoramic image, x∈[minRowIdx, maxRowIdx], minRowIdx isa minimum value of a row-coordinate of the pixel in the human body area,maxRowIdx is a maximum value of the row-coordinate of the pixel in thehuman body area, minBodyDepth is a set minimum value of a depth value ofthe pixel in the human body area, maxBodyDepth is a set maximum value ofthe depth value of the pixel in the human body area, andbodyDepth∈[minBodyDepth, maxBodyDepth]; depth values of all pixels inthe sky area are set to a fixed value skyDepth, andskyDepth∈(maxBodyDepth, 255]; pixels (x₂, y₂) in the ground area arepartitioned into a fixed depth value area and a gradient depth valuearea; a range of the row coordinates of the fixed depth area is[2maxRowIdx-imgH, imgH], where imgH is a height of the panoramic image,that is, a maximum value of the row coordinate of the pixel in thepanoramic image, the depth value of the pixel in the fixed depth area isset to the fixed value maxBodyDepth; an area outside the fixed deptharea in the ground area is taken as the gradient depth value area, and adepth value of the pixel (x₂, y₂) in the gradient depth value area canbe calculated by a formula (2): $\begin{matrix}{{{gradulDepth} = {{edgeDepth} + \frac{y_{2} \cdot \begin{pmatrix}{{\max\mspace{11mu}{BodyDepth}} -} \\{edgeDepth}\end{pmatrix}}{lowIdx}}},} & (2)\end{matrix}$ in the formula (2), y₂ is the row coordinate of the pixel(x₂, y₂) in the panoramic image, y₂<2maxRowIdx-imgH, edgeDepth is a setfixed value, and edgeDepth∈[maxBodyDepth, skyDepth).
 12. The portableterminal according to claim 9, wherein the generating an asteroid viewunder a virtual viewpoint comprises: setting a coordinate of the virtualviewpoint; wherein a real viewpoint of the asteroid image is directlyabove the asteroid image, the virtual viewpoint is set on a unitcircular trajectory centered on the real viewpoint and parallel to theasteroid image, the coordinate of the virtual viewpoint is (x, y), andx=cos (θ), y=sin(θ), θ∈[0, 2·π]; calculating a translation matrix T fromthe real viewpoint to the virtual viewpoint; wherein T is a 3*3 matrix,and is calculated by a formula (9): $\begin{matrix}{\{ \begin{matrix}{T_{x} = x} \\{T_{y} = y} \\{T_{z} = 0}\end{matrix} ;} & (9)\end{matrix}$ calculating a rotation matrix R from the real viewpoint tothe virtual viewpoint; wherein R is a 3*3 matrix, and is calculated by aformula (10): $\begin{matrix}\{ {\begin{matrix}{R_{x} = {x \cdot \frac{\pi}{60}}} \\{R_{y} = {y \cdot \frac{\pi}{60}}} \\{R_{z} = 0}\end{matrix};}  & (10)\end{matrix}$ generating the asteroid view under the virtual viewpointby using a 3D warping algorithm according to the asteroid image and theasteroid depth map; wherein the 3D warping algorithm comprises:acquiring a two-dimensional image coordinate in an RGB image of theasteroid image and a corresponding depth value in the asteroid depthmap, and backprojecting a two-dimensional coordinate point q to a realthree-dimensional coordinate point P; rotating or translating the realthree-dimensional coordinate point P to generate P′; re-projecting therotated or translated virtual three-dimensional coordinate point P′ to atwo-dimensional image plane under the virtual viewpoint to generate atwo-dimensional coordinate point q′; wherein the depth value reflects afront and back occlusion relationship between three-dimensional objectsin a projection process; wherein a projection formula of the asteroidview under the virtual viewpoint is shown as a formula (11):q′=K·R·K ⁻¹ ·q+K·T  (11), in the formula (11), wherein P is the realthree-dimensional coordinate point, q is the two-dimensional coordinatepoint of P projected onto the two-dimensional image plane, q=K·P, P′ isthe virtual three-dimensional coordinate point, a relationship betweenthe virtual three-dimensional coordinate point P′ and the realthree-dimensional coordinate point P satisfies P′=R·P+T; q′ is thetwo-dimensional coordinate point of P′ projected onto thetwo-dimensional image plane, q′=K·P′, K is an internal parameter matrixof a camera, a virtual camera and a real camera are arranged to have asame internal parameter.
 13. The portable terminal according to claim12, wherein in the generated asteroid view under the virtual viewpoint,since there are n virtual viewpoints (x, y), n asteroid views under then virtual viewpoints are generated, and n>1.
 14. The portable terminalaccording to claim 12, wherein, in the asteroid view under the virtualviewpoint generated by using the 3D warping algorithm, a void areawithout pixel information generated by an object in the originalasteroid image due to the front and back occlusion is filled with anadjacent pixel point.
 15. The portable terminal according to claim 9,wherein the generating the 3D asteroid dynamic graph by rendering theplurality of asteroid views under the plurality of virtual viewpointscomprises: using n virtual viewpoints on the unit circular trajectory togenerate n asteroid views under the n virtual viewpoints, synthesizingand rendering the n asteroid views in an order to generate the 3Dasteroid dynamic graph, and n is a positive integer.